When Gurbaksh Chahal was 16, he dropped out of high school to focus on his online advertising startup, ClickAgents.

Two years later, he sold it for $40 million to ValueClick. BlueLithium, his next startup, also focused on online advertising and sold for $300 million to Yahoo in 2007.

Now the serial entrepreneur is deep into his third online advertising startup, San Francisco's RadiumOne. This time, he's looking at social and mobile advertising, and how best to display online advertisements based on a person's use of Twitter and other online social activity.

RadiumOne began as gWallet, its a loyalty and rewards program, which allows Internet users to receive virtual currency for doing things such as answering advertising-sponsored surveys. It has since expanded to RadiumOne.

Along the way, Chahal also wrote a book and appeared on Oprah Winfrey's show and on the reality television show "Secret Millionaire."

He recently spoke about online advertising trends and how the recent mass shooting at a Wisconsin Sikh temple inspired him to start a nonprofit that works to end hate crimes. The campaign begins Nov. 12.

This conversation has been edited for length and clarity.

Q:What is RadiumOne?

A: RadiumOne does social advertising.

Before, BlueLithium was about if you went to GM's website, you'll start seeing GM advertisements wherever you go. But now people go less and less to GM's website, and they interact with brands on Facebook and Twitter (and other social media sites such as YouTube).

So if you saw a trailer for an upcoming movie, by clicking on a link, we'd be able to see that interaction. Let's say it's for "Prometheus," so you'll start to see "Prometheus" ads. It is extending all the different social activity you do to make advertising smarter.

The thing we (also) realize is that you are what you share. It's not about how many friends you have on Facebook or how many followers you have on Twitter. It's really about what you share, and who interacts with it.

If you put up a link on Twitter, who actually clicks on it? That's how we're able to build something called the "Share-Graph."

If you're interested in a movie because you just clicked on the trailer, chances are your close circle will also have the same affinity toward it. If you're an American Express cardholder, your close friends are likely to be candidates for an American Express card too.

The premise is to look at raw social activity on the Internet, and take the right data from there to make advertising smarter.

Q:There's been a lot of discussion about online privacy and proposals such as "do not track," which would prevent advertisers from tracking consumers' Web browsing activity. What do you think about it?

A: Every time someone asks me about new legislation, I basically ignore it. I know our politicians aren't that stupid, because if they do that, it's actually going to provide a recession to the entire Internet.

If the economy is already bad, the last thing you want to do is to put a recession behind the most growing sector. Everything is derived from the method of cookies (software used to track the websites a person visits). That feeds off of an experience that you get for free.

If you take that component out of it, nobody is going to track. We're going to go back to the old 1998-type advertising. We're going to see a lot of pop-up and unrelated advertising. You're probably going to have to start paying for stuff.

It's definitely not going to go in that direction because that's like the depression of the Internet. In the reality of it, the people who don't like that are really 1 percent or less. For the 1 percent who don't like it, there are methods for removing it and opting out and all that other stuff, but the 99 percent are fine.

Q:What is the future of online advertising?

A: This wave is social, so it's just understanding the things you do socially to make advertising more social.

The wave after that is: How do you connect the dots from mobile and Web and desktop and all the different things you're doing? How do you make mobile ads (work)? That will probably take three to five years to solve, so we're in the beginning stages of that.

Q:What is your plan for RadiumOne?

A: We're three years into it, with 200 employees worldwide. We're growing faster than any of my other companies. I think 12 months from now, we'll be in a prime position to be an IPO candidate for Wall Street.

Q:What happened to gWallet? Are we seeing less in-game advertising?

A: It's not going to grow as fast as social or mobile advertising. Rewards-based advertising has been around for a long time, and this is a component of it. It will continue to grow at its pace but the bigger opportunities are in social and mobile.

The reason (the company launched as gWallet) was when we started, my non-compete didn't expire until a certain time, when I could get back into display advertising. As soon as that could happen, we rebranded as Radium-One.

Q:What else are you doing?

A: I started my own nonprofit foundation called BeProud ( www.beproud.org). We're going to do our campaign launch in November. It's a social and mass-media campaign to end hate, inspired by the recent hate tragedies.

We have an interesting video campaign for it and a social component so people can easily get involved through Facebook, Twitter and YouTube. We've gotten a lot of celebrities involved to show their support. Outside of RadiumOne, that's where my time goes.